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Olson KL, Hayduk L, Cree M, Tsui Y, Quan H, Hanson J, Lawlor P. The variations in symptom clusters related to well-being in palliative care patients during the final weeks of life. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.19612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
19612 Background: The purpose of this study was to determine whether the relationships between symptoms and well-being, as experienced by palliative care patients, changed as patients approached death. Methods: Data were extracted from a database that included Edmonton Symptom Assessment System scores collected from palliative care patients on Day 7 of Weeks 5 (n=123), 2 (n=115), and 1 (n=113) prior to death between 1995 and 2000. The model contained 18 effect parameters. Based on standard sample size requirements for structural equation modeling of 10 cases per indicator variable, the study was adequately powered for all three time points. The majority of patients had advanced cancer and were receiving care in either a tertiary palliative care or hospice setting. All participants had Folstein Mini- Mental Status Examination scores of 22 or higher at the time of original data collection. A causal model, based primarily on clinical discussions, linking pain, anxiety, nausea, shortness of breath, drowsiness, loss of appetite, tiredness, depression, and well-being was proposed. The model was tested against the data from all three time points, using LISREL, version 8.7.2s. Results: The model fit the data for all time points, but was revised slightly based on the modification indices. The final Goodness of Fit Test values were χ2= 4.2 (d.f.=8, p=.84), χ2= 13.3 (d.f.=9, p=.15), and χ2= 5.5 (d.f.=9, p=.79) respectively. With respect to tiredness, depression and well-being, the model explained at least 70% of the variance at Week 5, between 57% and 83% of the variance at Week 2, and 42% to 58% of the variance in Week 1. Nausea was unimportant in all of the models. The two strongest effects, persisting over all three time periods, were those linking anxiety to depression, and drowsiness to tiredness, reflecting strong stability in patient rankings even as health declined and treatment changed. Conclusions: The symptom clusters in this study changed over time, in disagreement with existing research that assumes the relationships between symptoms within symptom clusters remain stable. An improved understanding of alterations in symptom clusters may contribute to improved control of patient comfort, quality of life, and quality of death. No significant financial relationships to disclose.
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Hu G, Yao J, Quan H, Chen W. SU-FF-J-39: A Comparison of Two Methods Extracting Respiratory Information From Ultrasound Video. Med Phys 2007. [DOI: 10.1118/1.2760544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Wang FL, Schoplocher D, Cui XJ, Quan H. Sources of Diagnosis in Administrative Data: Considerations in Epidemiologic Research and Surveillance. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s49-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Quan H. ICD-10-CA/CCI coding algorithms for defining clinical variables to assess outcome after aortic and mitral valve replacement surgery. Can J Cardiol 2006; 22:153-4. [PMID: 16485052 PMCID: PMC2538989 DOI: 10.1016/s0828-282x(06)70256-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Implementation of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Canada (ICD-10-CA) and the Canadian Classification of Interventions (CCI) coding system presents challenges for using Canadian administrative data. Thus, a multi-step process was conducted to develop ICD-10-CA/CCI coding algorithms to define nine comorbidities and three procedures. These clinical variables have been used in ICD-9-CM data for risk adjustment in assessment of outcomes after aortic and mitral valve replacement surgery. Among patients included in the ICD-9-CM data during 1999 and 2001 and in the ICD-10-CA/CCI data during 2002 and 2003 in a Canadian Health Region, frequencies of the nine comorbidities and the three procedures remained generally similar across databases. The newly developed ICD-10-CA/CCI and previous ICD-9-CM coding algorithms are comparable in detecting these clinical variables. However, performance of ICD-10-CA/CCI coding algorithms in risk adjustment should be evaluated in a larger database.
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Wang FL, Quan H, Svenson L, Schopflocher D. 503: Differences in Prevalence of Congenital Anomalies between Chinese and Non-Chinese Live Births, Alberta, Canada, 1983–2003. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s126b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Hawkey CJ, Laine L, Simon T, Quan H, Shingo S, Evans J. Incidence of gastroduodenal ulcers in patients with rheumatoid arthritis after 12 weeks of rofecoxib, naproxen, or placebo: a multicentre, randomised, double blind study. Gut 2003; 52:820-6. [PMID: 12740337 PMCID: PMC1773685 DOI: 10.1136/gut.52.6.820] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Previous studies in patients with osteoarthritis have suggested that the selective cyclooxygenase (COX)-2 inhibitor rofecoxib results in less gastrointestinal damage than non-selective non-steroidal antiinflammatory drugs (NSAIDs). This study compared the incidence of endoscopically detected gastroduodenal ulcers in rheumatoid arthritis patients treated with rofecoxib or a non-selective NSAID. METHODS In this multicentre, randomised, double blind, 12 week study, patients with rheumatoid arthritis were allocated to rofecoxib 50 mg once daily (n=219), naproxen 500 mg twice daily (n=220), or placebo (n=221). Endoscopy was performed at baseline and at six and 12 weeks. Lifetable analysis and log rank tests were used to analyse the incidence of gastroduodenal ulcers > or =3 mm. Gastric or duodenal ulcers > or =5 mm and erosions were also evaluated as secondary end points. Tolerability was assessed by adverse events. RESULTS The cumulative incidence of ulcers > or =3 mm at 12 weeks was significantly higher in patients on naproxen (25.5%) than in patients receiving rofecoxib (6.8%; difference 18.7% (95% confidence interval (CI) 11.7%, 25.7%); p<0.001) or placebo (2.9%; difference 22.6% (95% CI 16.1%, 29.1%); p<0.001). The difference between rofecoxib (6.8%) and placebo (2.9%) did not reach statistical significance (p=0.066). Results were similar for ulcers > or =5 mm and for mean changes from baseline in the number of gastroduodenal erosions. The overall incidence of clinical adverse events was similar among treatment groups (61% of patients on placebo, 62% in patients on rofecoxib, and 66% in patients on naproxen). CONCLUSIONS Rofecoxib 50 mg daily (twice the dose recommended for this patient population) resulted in a lower incidence of endoscopically detected gastroduodenal ulcers and erosions than treatment with naproxen 500 mg twice daily.
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Hunt RH, Harper S, Callegari P, Yu C, Quan H, Evans J, James C, Bowen B, Rashid F. Complementary studies of the gastrointestinal safety of the cyclo-oxygenase-2-selective inhibitor etoricoxib. Aliment Pharmacol Ther 2003; 17:201-10. [PMID: 12534404 DOI: 10.1046/j.1365-2036.2003.01407.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Cyclo-oxygenase-2-selective non-steroidal anti-inflammatory drugs are intended to preserve cyclo-oxygenase-1-mediated gastroprotection and platelet function, whilst inhibiting cyclo-oxygenase-2-mediated inflammation. AIM To assess the gastrointestinal safety of the cyclo-oxygenase-2-selective inhibitor etoricoxib vs. non-selective non-steroidal anti-inflammatory drugs. METHODS Two randomized, double-blind, placebo- and active-controlled studies were performed: (i) daily faecal red blood cell loss was measured in 62 subjects receiving etoricoxib (120 mg once daily), ibuprofen (800 mg t.d.s.) or placebo for 28 days; (ii) the incidence of endoscopically detectable gastric/duodenal ulcers was determined in 742 osteoarthritis or rheumatoid arthritis patients receiving etoricoxib (120 mg once daily), naproxen (500 mg b.d.) or placebo over 12 weeks. RESULTS In the first study, the between-treatment ratio of faecal blood loss for etoricoxib vs. placebo (1.06) was not significantly different from unity; however, the ratios for ibuprofen vs. placebo (3.26) and etoricoxib (3.08) were significantly greater than unity (P < 0.001). In the second study, the incidence of ulcers of > or = 3 mm with naproxen (25.3%) was significantly higher than that with etoricoxib (7.4%) or placebo (1.4%; P < 0.001); the results were similar for ulcers of > or = 5 mm. CONCLUSIONS The reduced toxicity of etoricoxib (less faecal blood loss and fewer endoscopically detectable lesions) suggests that use of this drug will may be associated with a reduced incidence of gastrointestinal perforations, ulcers and bleeds.
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Abstract
PURPOSE Among patients who had undergone coronary angiography, we sought to determine the proportion of chelation therapy users, their sociodemographic and clinical characteristics, and the association of chelation therapy with subsequent revascularization. METHODS We studied all patients who underwent coronary angiography in the province of Alberta, Canada, during 1995 and 1996. The cohort was followed for up to 6 years to determine subsequent revascularization status. Use of chelation therapy was determined by a mailed survey 1 year after angiography. RESULTS Among the 5854 patients who responded to the mail survey (70% response rate), 210 (3.6%) reported current use of chelation therapy and 252 (4.3%) reported past use. Current use of chelation therapy was associated with extensive coronary artery disease (adjusted odds ratio [OR] = 3.3; 95% confidence interval [CI]: 1.9 to 5.7 for 3-vessel disease; and OR = 2.7; 95% CI: 1.2 to 6.0 for left main disease, as compared with those with normal anatomy) and the absence of diabetes (OR = 0.6; 95% CI: 0.4 to 0.9). Current users were less likely to have undergone percutaneous transluminal coronary angioplasty (OR = 0.7; 95% CI: 0.5 to 0.9) and coronary artery bypass graft (CABG) surgery (OR = 0.3; 95% CI: 0.2 to 0.5) in the first year after angiography, but were as likely as nonusers of chelation therapy to have undergone CABG surgery in the subsequent 3- to 5-year period (adjusted hazard ratio [HR] = 1.1; 95% CI: 0.7 to 1.9). Past use of chelation therapy was associated with a history of CABG surgery before coronary angiography (OR = 1.6; 95% CI: 1.1 to 2.3) and extensive coronary artery disease. Past users were also more likely to have undergone CABG surgery in the follow-up period (HR = 1.7; 95% CI: 1.1 to 2.6). CONCLUSIONS About 8% of patients who underwent cardiac catheterization for coronary artery disease were using or had previously tried chelation therapy. Users may have foregone revascularization in favor of this less invasive yet unproven treatment, with some users subsequently undergoing conventional treatment after chelation. Alternatively, some patients may have turned to chelation as a "last resort" after having been judged unsuitable for revascularization.
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Abstract
Some clinical trials aim to demonstrate therapeutic equivalence on multiple primary endpoints. For example, therapeutic equivalence studies of agents for the treatment of osteoarthritis use several primary endpoints including investigator's global assessment of disease activity, patient's global assessment of response to therapy, and pain. In this paper, thoughts on simultaneous equivalence assessment on three endpoints are presented. As pointed out by Berger and Hsu (1996), the conventional intersection-union test can be conservative. Simulation and computation are conducted to provide an insight on the conservativeness. We also provide a method to lower the confidence level and at the same time maintain the type I error when endpoints have normal distributions and are independent. If, in a particular analysis, the goal is to demonstrate equivalence on as many endpoints as possible, a step-up procedure can be used for selecting those endpoints for which equivalence may be demonstrated. This step-up procedure at the same time controls experimentwise error rate. The techniques are illustrated by a data example.
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Abstract
UNLABELLED Background and Purpose-- Carotid endarterectomy (CEA) is an important method of stroke prevention, but its usage in Canada is not well known. The indications for CEA have been well informed by the recent clinical trials, but the impact of this information on the rate and regional variation in the rate of CEA is unknown. This study sought to determine the rate and the regional variation in the rate of CEA in Canada, its provinces, and census divisions for 1994-1997. METHODS Discharge data from all hospitals in Canada except Quebec were obtained from the Canadian Institute for Health Information for 1994-1997 and were searched for CEA by residential site. Rates and variations in rates were calculated. RESULTS The national age- and sex-adjusted rate per 100 000 people of CEA for those aged >/=40 years rose from 31.7 in 1994 to 40.5 in 1997. Provincial rates in 1997 varied from a low of 25.7 in Saskatchewan to high of 82.8 in Prince Edward Island. The census division rates varied even more, from a low of 0 in several divisions to a high of 179. CONCLUSIONS The recent slight increase in CEA rates may reflect the release of new efficacy results for CEA, especially for asymptomatic carotid stenosis, but the rates are still far below US levels. The marked regional variation in rates may reflect differing views on the appropriateness of indications such as asymptomatic carotid stenosis for CEA and the inconsistency of published clinical practice guidelines.
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Ghali WA, Quan H, Brant R, van Melle G, Norris CM, Faris PD, Galbraith PD, Knudtson ML. Comparison of 2 methods for calculating adjusted survival curves from proportional hazards models. JAMA 2001; 286:1494-7. [PMID: 11572743 DOI: 10.1001/jama.286.12.1494] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Adjusted survival curves are often presented in medical research articles. The most commonly used method for calculating such curves is the mean of covariates method, in which average values of covariates are entered into a proportional hazards regression equation. Use of this method is widespread despite published concerns regarding the validity of resulting curves. OBJECTIVE To compare the mean of covariates method to the less widely used corrected group prognosis method in an analysis evaluating survival in patients with and without diabetes. In the latter method, a survival curve is calculated for each level of covariates, after which an average survival curve is calculated as a weighted average of the survival curves for each level of covariates. DESIGN, SETTING, AND PATIENTS Analysis of cohort study data from 11 468 Alberta residents undergoing cardiac catheterization between January 1, 1995, and December 31, 1996. MAIN OUTCOME MEASURES Crude and risk-adjusted survival for up to 3 years after cardiac catheterization in patients with vs without diabetes, analyzed by the mean of covariates method vs the corrected group prognosis method. RESULTS According to the mean of covariates method, adjusted survival at 1044 days was 94.1% and 94.9% for patients with and without diabetes, respectively, with misleading adjusted survival curves that fell above the unadjusted curves. With the corrected group prognosis method, the corresponding survival values were 91.3% and 92.4%, with curves that fell more appropriately between the unadjusted curves. CONCLUSIONS Misleading adjusted survival curves resulted from using the mean of covariates method of analysis for our data. We recommend using the corrected group prognosis method for calculating risk-adjusted curves.
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Abstract
OBJECTIVES To determine the frequency with which commonly coded clinical variables are complications, as opposed to baseline comorbidities, and to compare the results of 2 risk-adjusted outcome analyses for coronary artery bypass graft surgery for which we either (a) ignored, or (b) used the available "diagnosis-type indicator." DESIGN Analysis of existing administrative data. SETTING Twenty-three Canadian hospitals. PATIENTS A total of 50,357 coronary artery bypass graft surgery cases. MEASUREMENTS AND MAIN RESULTS Among 21 clinical variables whose definitions involve the diagnosis-type indicator, 14 were predominantly (> or =97%) baseline risk factors when present. Seven variables were often complication diagnoses: renal disease (when present, 13% coded as complications), recent myocardial infarction (15%), peptic ulcer disease (15%), congestive heart failure (17%), cerebrovascular disease (26%), hemiplegia (34%), and severe liver disease (35%). The results of risk adjustment analyses predicting in-hospital mortality differed when the diagnosis-type indicator was either used or ignored, and as a result, adjusted hospital mortality rates and rankings changed, often dramatically, with rankings increasing for 10 hospitals, decreasing for 9 hospitals, and remaining the same for only 4 hospitals. CONCLUSIONS The results of analyses performed using the diagnosis-type indicator in Canadian administrative data differ considerably from analyses that ignore the indicator. The widespread introduction of such an indicator should be considered in other countries, because risk-adjustment analyses performed without a diagnosis-type indicator may yield misleading results.
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Devereaux PJ, Manns BJ, Ghali WA, Quan H, Guyatt GH. Reviewing the reviewers: the quality of reporting in three secondary journals. CMAJ 2001; 164:1573-6. [PMID: 11402795 PMCID: PMC81111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND Secondary journals such as ACP Journal Club (ACP), Journal Watch (JW) and Internal Medicine Alert (IMA) have enormous potential to help clinicians remain up to date with medical knowledge. However, for clinicians to evaluate the validity and applicability of new findings, they need information on the study design, methodology and results. METHODS Beginning with the first issue in March 1997, we selected 50 consecutive summaries of studies addressing therapy or prevention and internal medicine content from each of the ACP, JW and IMA. We evaluated the summaries for completeness of reporting key aspects of study design, methodology and results. RESULTS All of the summaries in ACP reported study design, as compared with 72% of the summaries in JW and IMA (p < 0.001). In summaries of randomized controlled trials the 3 secondary journals were similar in reporting concealment of patient allocation (none reported this), blinding status of participants (ACP 62%, JW 70% and IMA 70% [p = 0.7]), blinding status of health care providers (ACP 12%, JW 4% and IMA 4% [p = 0.4]) and blinding status of judicial assessors of outcomes (ACP 4%, JW 4% and IMA 0% [p = 0.4]). ACP was the only one to report whether investigators conducted an intention-to-treat analysis (in 38% of summaries [p < 0.001]), and it was more likely than the other 2 journals to report the precision of the treatment effect (as a p value or 95% confidence interval) (ACP 100%, JW 0% and IMA 55% [p < 0.001]). INTERPRETATION Although ACP provided more information on study design, methodology and results, all 3 secondary journals often omitted important information. More complete reporting is necessary for secondary journals to fulfill their potential to help clinicians evaluate the medical literature.
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Pereira J, Bruera E, Quan H. Palliative care on the net: an online survey of health care professionals. J Palliat Care 2001; 17:41-5. [PMID: 11324184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A survey was conducted to explore Internet use by palliative care health professionals (HCP). The survey was placed on the World Wide Web with an underlying database, and palliative care HCP were invited to participate via a palliative-care-related website, listserv, and newsletter. A total of 417 evaluable responses were received over a four-month period. Of these, 36% indicated they were from physicians and 30% from nurses, a third of respondents were practicing palliative care full time. Although 63% of respondents were from North America, regions from all over the world were represented. Eighty-eight percent of respondents were searching the Internet for clinical information, 80% were using email, 69% were accessing online medical journals, and 59% were subscribers to a palliative-care-related listserv or newsgroup. This survey illustrates the global outreach of the Internet and draws attention to the growing interest in the use of the Internet for education, research, and clinical use. Further development of online resources should address the needs of users. Evaluation of these resources is called for.
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Hemmelgarn BR, Ghali WA, Quan H. A case study of hospital closure and centralization of coronary revascularization procedures. CMAJ 2001; 164:1431-5. [PMID: 11387915 PMCID: PMC81069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND Despite nation-wide efforts to reduce health care costs through hospital closures and centralization of services, little is known about the impact of such actions. We conducted this study to determine the effect of a hospital closure in Calgary and the resultant centralization of coronary revascularization procedures from 2 facilities to a single location. METHODS Administrative data were used to identify patients who underwent coronary artery bypass grafting (CABG), including those who had combined CABG and valve procedures, and patients who underwent percutaneous transluminal angioplasty (PTCA) in the Calgary Regional Health Authority from July 1994 to March 1998. This period represents the 21 months preceding and the 24 months following the March 1996 hospital closure. Measures, including mean number of discharges, length of hospital stay, burden of comorbidity and in-hospital death rates, were compared before and after the hospital closure for CABG and PTCA patients. Multivariate analyses were used to derive risk-adjustment models to control for sociodemographic variables and comorbidity. RESULTS The number of patients undergoing CABG was higher in the year following than in the year preceding the hospital closure (51.6 per 100,000 before v. 67.3 per 100,000 after the closure); the same was true for the number of patients undergoing PTCA (129.8 v. 143.6 per 100,000). The burden of comorbidity was significantly higher after than before the closure, both for CABG patients (comorbidity index 1.3 before v. 1.5 after closure, p < 0.001) and for PTCA patients (comorbidity index 1.0 before v. 1.1 after, p = 0.04). After adjustment for comorbidity, the mean length of hospital stay was significantly lower after than before the closure for CABG patients (by 1.3 days) and for PTCA patients (by 1.0 days). The adjusted rates of death were slightly lower after than before the closure in the CABG group. The adjusted rates of death or CABG in the PTCA group did not differ significantly between the 2 periods. INTERPRETATION Hospital closure and the centralization of coronary revascularization procedures in Calgary was associated with increased population rates of procedures being performed, on sicker patients, with shorter hospital stays, and, for CABG patients, a trend toward more favourable short-term outcomes. Our findings indicate that controversial changes to the structure of the health care system can occur without loss of efficiency and reduction in quality of care.
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Devereaux PJ, Manns BJ, Ghali WA, Quan H, Lacchetti C, Montori VM, Bhandari M, Guyatt GH. Physician interpretations and textbook definitions of blinding terminology in randomized controlled trials. JAMA 2001; 285:2000-3. [PMID: 11308438 DOI: 10.1001/jama.285.15.2000] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT When clinicians assess the validity of randomized controlled trials (RCTs), they commonly evaluate the blinding status of individuals in the RCT. The terminology authors often use to convey blinding status (single, double, and triple blinding) may be open to various interpretations. OBJECTIVE To determine physician interpretations and textbook definitions of RCT blinding terms. DESIGN AND SETTING Observational study undertaken at 3 Canadian university tertiary care centers between February and May 1999. PARTICIPANTS Ninety-one internal medicine physicians who responded to a survey. MAIN OUTCOME MEASURES Respondents identified which of the following groups they thought were blinded in single-, double-, and triple-blinded RCTs: participants, health care providers, data collectors, judicial assessors of outcomes, data analysts, and personnel who write the article. Definitions from 25 systematically identified textbooks published since 1990 providing definitions for single, double, or triple blinding. RESULTS Physician respondents identified 10, 17, and 15 unique interpretations of single, double, and triple blinding, respectively, and textbooks provided 5, 9, and 7 different definitions of each. The frequencies of the most common physician interpretation and textbook definition were 75% (95% confidence interval [CI], 65%-83%) and 74% (95% CI, 52%-90%) for single blinding, 38% (95% CI, 28%-49%) and 43% (95% CI, 24%-63%) for double blinding, and 18% (95% CI, 10%-28%) and 14% (95% CI, 0%-58%) for triple blinding, respectively. CONCLUSIONS Our study suggests that both physicians and textbooks vary greatly in their interpretations and definitions of single, double, and triple blinding. Explicit statements about the blinding status of specific groups involved in RCTs should replace the current ambiguous terminology.
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Torres GE, Yao WD, Mohn AR, Quan H, Kim KM, Levey AI, Staudinger J, Caron MG. Functional interaction between monoamine plasma membrane transporters and the synaptic PDZ domain-containing protein PICK1. Neuron 2001; 30:121-34. [PMID: 11343649 DOI: 10.1016/s0896-6273(01)00267-7] [Citation(s) in RCA: 242] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PDZ domain-containing proteins play an important role in the targeting and localization of synaptic membrane proteins. Here, we report an interaction between the PDZ domain-containing protein PICK1 and monoamine neurotransmitter transporters in vitro and in vivo. In dopaminergic neurons, PICK1 colocalizes with the dopamine transporter (DAT) and forms a stable protein complex. Coexpression of PICK1 with DAT in mammalian cells and neurons in culture results in colocalization of the two proteins in a cluster pattern and an enhancement of DAT uptake activity through an increase in the number of plasma membrane DAT. Deletion of the PDZ binding site at the carboxyl terminus of DAT abolishes its association with PICK1 and impairs the localization of the transporter in neurons. These findings indicate a role for PDZ-mediated protein interactions in the localization, expression, and function of monoamine transporters.
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Bruera E, Neumann C, Brenneis C, Quan H. Frequency of symptom distress and poor prognostic indicators in palliative cancer patients admitted to a tertiary palliative care unit, hospices, and acute care hospitals. J Palliat Care 2001; 16:16-21. [PMID: 11019503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The Edmonton Regional Palliative Care Program was established to increase access to palliative care for terminal cancer patients in the region. Inpatient care is delivered, in decreasing order to distress, at the tertiary palliative care unit, by consult teams in acute care facilities, and in hospices. We reviewed the admission data for all patients discharged from the program between November 1, 1997, and October 31, 1998, in order to determine if demographical and clinical variables suggested appropriate use of the three levels of care. Patients admitted to the tertiary palliative care unit were significantly younger than those admitted to acute care of hospices (61 years versus 68 years and 71 years respectively, p < 0.0001), had a higher frequency of positive screening for alcoholism in the CAGE questionnaire (27% versus 16% and 14% respectively, p < 0.0001), and a higher frequency of poor prognostic pain syndromes as compared to acute care admissions (87% versus 65%, p < 0.0001). Overall, frequency of symptoms and severe symptoms was significantly higher in patients admitted to the palliative care unit than those admitted to the other two settings. Our results suggest that patients with demographic and clinical indications of higher distress are more frequently admitted to the tertiary palliative care unit. The clinical tools are useful predictors of utilization that can be used for monitoring health care delivery.
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Hemmelgarn BR, Ghali WA, Quan H, Brant R, Norris CM, Taub KJ, Knudtson ML. Poor long-term survival after coronary angiography in patients with renal insufficiency. Am J Kidney Dis 2001; 37:64-72. [PMID: 11136169 DOI: 10.1053/ajkd.2001.20586] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cardiovascular disease is common among dialysis patients, but much less is known regarding non-dialysis-dependent renal insufficiency (NDDRI) and its association with cardiac disease. We undertook a study to assess the impact of renal insufficiency on survival post-coronary angiography by comparing three groups of patients: dialysis-dependent patients, patients with NDDRI (creatinine > 2.3 mg/dL), and a reference group with creatinine levels less than 2.3 mg/dL and not on dialysis therapy. We used a prospective cohort that consisted of all patients undergoing coronary angiography in Alberta, Canada, from January 1, 1995, to December 31, 1997. Of the 16,989 patients, 196 patients (1.2%) were on dialysis therapy, 262 patients (1.5%) had NDDRI, and 16,531 patients (97.3%) formed the reference group. Mortality rates 1 year after angiography were 30.2% for patients with NDDRI, 15.8% for dialysis patients, and 4.1% for the reference group. Compared with the reference group, crude 4-year survival was significantly worse for dialysis patients and those with NDDRI, with hazard ratios of 4.05 (95% confidence interval, 3.02 to 5.42) and 7.32 (95% confidence interval, 5.97 to 8.97), respectively. Even after adjusting for clinical risk factors, survival remained worse for dialysis patients and those with NDDRI, with hazard ratios of 2.59 (95% confidence interval, 1.92 to 3.49) and 2.51 (95% confidence interval, 2.02 to 3.12), respectively. We conclude that renal insufficiency, both dialysis dependent and non-dialysis dependent, is an independent risk factor for increased mortality and poor long-term survival among patients undergoing coronary angiography.
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Lanza F, Schwartz H, Sahba B, Malaty HM, Musliner T, Reyes R, Quan H, Graham DY. An endoscopic comparison of the effects of alendronate and risedronate on upper gastrointestinal mucosae. Am J Gastroenterol 2000; 95:3112-7. [PMID: 11095326 DOI: 10.1111/j.1572-0241.2000.03258.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The nitrogen-containing bisphosphonates alendronate and risedronate have been reported to have upper gastrointestinal (GI) safety and tolerability profiles comparable to those of placebo. Nevertheless, both agents have demonstrated similar potential for irritation of gastric mucosa at high doses in preclinical studies. The present study compared the potential for alendronate and risedronate to produce endoscopic upper GI mucosal irritation using the highest approved dosage regimens for the two agents. METHODS This was a multicenter, randomized, parallel-group, double-blind, placebo-controlled trial in which a total of 235 patients (men or postmenopausal women, aged 45-80 yr) with normal upper GI endoscopy at baseline received 28-day treatments with the following: alendronate 40 mg/day (N = 90), risedronate 30 mg/day (N = 89), placebo (N = 36), or placebo with aspirin 650 mg q.i.d. for the last 7 days (N = 20). Endoscopy was repeated on day 29 using standardized scoring scales. RESULTS After 28 days of treatment, the alendronate and risedronate groups had comparable mean gastric and duodenal erosion scores that were significantly lower than those of the aspirin group. Esophageal scores were comparable in all groups. Gastric ulcers and/or large numbers of gastric erosions occurred in approximately 3% of alendronate and risedronate patients versus 60% with aspirin. Both bisphosphonates were clinically well tolerated. CONCLUSIONS The potential for gastroduodenal irritation is similar for alendronate and risedronate and is markedly less than for aspirin. The findings of this study, together with the large placebo-controlled clinical trial experience with both agents and extensive epidemiological data for alendronate, suggest that the risk for clinically important gastric irritation with these bisphosphonates is very low, even at the highest available doses.
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Ghali WA, Quan H, Norris CM, Dzavik V, Naylor CD, Mitchell LB, Brant R, Knudtson ML. Prognostic significance of diabetes as a predictor of survival after cardiac catheterization. APPROACH Investigators. Alberta Provincial Program for Outcome Assessment in Coronary Heart Disease. Am J Med 2000; 109:543-8. [PMID: 11063955 DOI: 10.1016/s0002-9343(00)00543-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE Diabetes is a recognized risk factor for the development of cardiac disease, but its importance as a prognostic factor among patients with known cardiovascular disease is less clear. We evaluated survival in patients with and without diabetes who underwent cardiac catheterization for presumed coronary artery disease. SUBJECTS AND METHODS We analyzed data from a prospective cohort study that captures detailed clinical information and longitudinal outcomes for all patients who undergo cardiac catheterization in Alberta, Canada. We studied 11,468 patients, 1959 (17%) of whom had diabetes. Logistic regression was used to model predictors of 1-year mortality, and proportional hazards analysis was used to model predictors of survival up to 3 years after cardiac catheterization. RESULTS One-year mortality was 7.6% for patients with diabetes versus 4.1% for those without diabetes (odds ratio = 1.9, 95% confidence interval [CI]: 1.6 to 2.3). After adjusting for other characteristics of the patients, including comorbid conditions, previous cardiac history, coronary anatomy, and renal function, the odds ratio for 1-year mortality was 1.1 (95% CI: 0.8 to 1.3). Similarly, the adjusted hazard ratio for longer term mortality was 1. 2 (95% CI: 1.0 to 1.4, mean follow-up of 702 days). CONCLUSIONS These results suggest that there is little or no independent association between diabetes and mortality for up to 3 years after cardiac catheterization. Estimates of short- to intermediate-term prognosis for diabetic patients with coronary artery disease should be based on the presence of other prognostic factors associated with diabetes.
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Watson DJ, Harper SE, Zhao PL, Quan H, Bolognese JA, Simon TJ. Gastrointestinal tolerability of the selective cyclooxygenase-2 (COX-2) inhibitor rofecoxib compared with nonselective COX-1 and COX-2 inhibitors in osteoarthritis. ARCHIVES OF INTERNAL MEDICINE 2000; 160:2998-3003. [PMID: 11041909 DOI: 10.1001/archinte.160.19.2998] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Most nonsteroidal anti-inflammatory drugs (NSAIDs) are nonselective cyclooxygenase (COX-1 and COX-2) inhibitors and are associated with a variety of upper gastrointestinal (GI) tract symptoms. The roles of COX-1 and COX-2 in the pathogenesis of these symptoms are unclear. To test whether COX-2 inhibition with rofecoxib would have greater GI tolerability than nonselective COX-1 and COX-2 inhibition, we compared the incidences of (1) treatment discontinuations for GI adverse events (AEs) and (2) prespecified dyspeptic-type GI AEs among patients with osteoarthritis treated with rofecoxib vs NSAIDs. METHODS A prespecified, combined analysis of investigator-reported GI AEs in all 8 double-blind, randomized, phase 2b/3 osteoarthritis trials of rofecoxib was conducted. Patients included men and women with osteoarthritis (N = 5435); there was no upper age limit for entry. Treatments tested included rofecoxib, 12.5, 25, or 50 mg (combined), vs ibuprofen, diclofenac, or nabumetone (combined). Primary outcomes were the time (by survival analysis) to (1) treatment discontinuation due to GI AEs and (2) first reported dyspeptic-type GI AE. Between-treatment comparisons were made by log-rank test. RESULTS The number of treatment discontinuations caused by GI AEs during 12 months was significantly lower (P=.02) with rofecoxib vs NSAIDs (8.2 vs 12.0 per 100 patient-years; relative risk, 0.70; 95% confidence interval, 0.52-0.94). The incidence of prespecified dyspeptic-type GI AEs during the first 6 months was significantly lower (P=.02) with rofecoxib vs NSAIDs (69.3 vs 85.2 per 100 patient-years; relative risk, 0.85; 95% confidence interval, 0.74-0.97). However, the difference between treatments in dyspeptic-type GI AEs was attenuated after 6 months. CONCLUSION Rofecoxib was associated with a lower incidence of treatment discontinuations due to GI AEs over 12 months and a lower incidence of dyspeptic-type GI AEs over 6 months than treatment with nonselective COX inhibitors, or NSAIDs. Arch Intern Med. 2000;160:2998-3003
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Sigthorsson G, Crane R, Simon T, Hoover M, Quan H, Bolognese J, Bjarnason I. COX-2 inhibition with rofecoxib does not increase intestinal permeability in healthy subjects: a double blind crossover study comparing rofecoxib with placebo and indomethacin. Gut 2000; 47:527-32. [PMID: 10986213 PMCID: PMC1728068 DOI: 10.1136/gut.47.4.527] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Acute and chronic use of non-steroidal anti-inflammatory drugs can increase intestinal permeability. Rofecoxib, which selectively inhibits cyclooxygenase 2 (COX-2), is a novel anti-inflammatory drug with the potential to produce minimal gastrointestinal toxic effects while retaining clinical efficacy. AIMS To assess the potential for rofecoxib to affect the intestine adversely, in comparison with placebo and indomethacin. SUBJECTS Thirty nine healthy subjects (aged 24-30 years). METHOD We performed a four period crossover trial to assess intestinal permeability before and after seven days of treatment. Permeability was measured by the urinary ratio of chromium-51 labelled ethylene diamine tetraacetate ((51)CrEDTA)/L-rhamnose (five hour collection). RESULTS Indomethacin 50 mg three times daily produced greater increases in intestinal permeability compared with placebo or rofecoxib (25 or 50 mg) (p< or = 0.001); rofecoxib was not significantly different from placebo. Mean day 7 to baseline ratios (95% confidence intervals) for (51)CrEDTA/L-rhamnose were 0.97 (0.82, 1.16), 0.80 (0.68, 0.95), 0.98 (0.82, 1.17), and 1.53 (1.27, 1.85) for placebo, rofecoxib 25 mg, rofecoxib 50 mg, and indomethacin groups, respectively. Rofecoxib was generally well tolerated. CONCLUSION In this study, treatment for one week with indomethacin 50 mg three times daily significantly increased intestinal permeability compared with placebo, while treatment with rofecoxib 25 mg or 50 mg daily did not. The absence of a significant effect of rofecoxib on intestinal permeability at doses at least twice those recommended to treat osteoarthritis was consistent with other studies that have demonstrated little or no injury to the gastrointestinal mucosa associated with rofecoxib therapy.
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Ghali WA, Rothwell DM, Quan H, Brant R, Tu JV. A Canadian comparison of data sources for coronary artery bypass surgery outcome "report cards". Am Heart J 2000; 140:402-8. [PMID: 10966537 DOI: 10.1067/mhj.2000.109222] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Prior comparisons of administrative versus clinical data for creating coronary artery bypass graft (CABG) surgery outcome "report cards" are all from the United States and yield inconsistent conclusions regarding the validity of administrative data report cards. In this study, we compared 2 CABG surgery outcome report cards for Ontario, Canada: one derived from clinical data from the Cardiac Care Network of Ontario and one derived from administrative data from the Canadian Institute for Health Information. METHODS Data from 4 fiscal years, 1992-93 through 1995-96, were used. The Canadian Institute for Health Information report card was derived from administrative data only. The Cardiac Care Network report card drew on prospectively collected clinical information that included variables such as left ventricular ejection fraction but also required linkages to the Canadian Institute for Health Information data for ascertainment of selected comorbidities and in-hospital mortality rates. Logistic regression models were used to calculate risk-adjusted death rates for each of the 9 hospitals performing CABG surgery in Ontario. RESULTS The risk-adjusted death rates were quite similar between data sources for 7 of the 9 hospitals. For 2 hospitals, rather large absolute differences in adjusted death rates of 0.58% and 0.64% were seen between report cards. There was a strong correlation between data sources for risk-adjusted hospital death rates (intraclass correlation coefficient = 0.927, P <.001) and for rankings of adjusted hospital death rates (Spearman correlation coefficient = 0.828, P =.02). CONCLUSION These results from Ontario, Canada, reveal general similarities between administrative and clinical data report cards for CABG surgery. However, clinical data are likely needed if individual hospitals are to be publicly scrutinized in outcome report cards.
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